Chlorine dioxide has been found to be an especially effective disinfectant. As used herein, the term “disinfecting” shall be used to include sanitizing, deodorizing, sterilizing, or otherwise destroying or reducing germ populations. The term “germs” as used herein shall include bacteria, yeasts, molds, viruses or any micro-organism whose presence, and numbers, are deemed inimical to human or animal welfare. Its use has been found to be particularly advantageous where microbes and/or organic odorants are sought to be controlled on and around foodstuffs, as chlorine dioxide functions without the formation of undesirable side products such as chloramines or chlorinated organic compounds that can be produced when elemental chlorine is utilized for the same or similar purposes.
Additionally, at concentrations which have been found to be effective for deodorization and for most antimicrobial applications, chlorine dioxide gas is also generally considered as safe for human contact because the concentrations required are so low.
Certain difficulties are encountered with the use of chlorine dioxide in practice, however. Chlorine dioxide gas can be toxic to humans at concentrations greater than 1,000 ppm and it can be explosive at partial pressures above about 0.1 atmosphere. Therefore, chlorine dioxide gas is not manufactured and shipped under pressure like other industrial gases, and conventional methods of on-site manufacture require not only expensive generation equipment but also high levels of operator skill to avoid generating dangerously high concentrations. These problems have substantially limited the use of chlorine dioxide to large commercial applications, such as water treatment and poultry processing, where the consumption of chlorine dioxide is sufficiently large that it can justify the capital and operating costs of expensive equipment and skilled operators for on-site manufacture. However, it is not practical to ship chlorine dioxide as a concentrated gas to the medium or small users.
It has thus become common practice to employ a chlorine dioxide-liberating compound such as sodium chlorite powder which is much safer from the standpoints of storage, shipping and handling. Generation of the chlorine dioxide from sodium chlorite or other chlorine dioxide liberating compound is usually effected by addition of acid, bleach (hypochlorite), or chlorine to the chlorine dioxide liberating compound.
However, the composition obtained from the interaction of the relatively high concentrations of sodium chlorite and acid materials used can be injurious to health. Significantly, the toxicity problem imposes severe limitations on the general utility of the disinfectant composition, particularly with respect to the treatment of human beings.
Methods have been developed in an attempt to overcome the aforementioned problems, but improved methods of generating chlorine dioxide on a small scale are still desired.